JD took an accident which had nothing to do with cars to complain about how unfairly car drivers are being treated, harping on about that very annoying myth that citizen car driver is oh so important that his free reign must never be curtailed. as if all of traffic (and with it a lof of public space and money) wasn't already tailored to fit the interests of car drivers.
fixed-brakeless doesn't mean one can't stop. it's different to trials or bmx brakeless. it's a different technique of braking. whether that's a smart thing to use in a busy city is another question, but it's by far not the murder weapon you make it out to be.
with a bike it takes a lot of bad luck to hurt someone else severely; you might knock someone down, but luckily that very, very rarely ends in serious injuries or death. source (1) states 32 people were killed by cyclists in the last 10 years. source (2) states that in 2015 alone there were 408 pedestrians killed and 100 cyclists (assuming here that the vast majority of those involved cars). a car is on another level of potential destruction, hence different rules apply.
(1) https://cf-particle-html.eip.telegraph.co.uk/786119b7-2dba-4f5f-8565-045f1672329a.html
(2) http://www.brake.org.uk/facts-resources/1653-uk-road-casualties
of course it is. 7C. https://www.nidirect.gov.uk/articles/rules-pedestrians-1-35